55154521221 has 8 divisors (see below), whose sum is σ = 73569797184. Its totient is φ = 36754463040.

The previous prime is 55154521211. The next prime is 55154521237. The reversal of 55154521221 is 12212545155.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 55154521221 - 2²¹ = 55152424069 is a prime.

It is a super-2 number, since 2×55154521221² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55154521211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3795985 + ... + 3810486.

It is an arithmetic number, because the mean of its divisors is an integer number (9196224648).

Almost surely, 2^55154521221 is an apocalyptic number.

It is an amenable number.

55154521221 is a deficient number, since it is larger than the sum of its proper divisors (18415275963).

55154521221 is a wasteful number, since it uses less digits than its factorization.

55154521221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7608891.

The product of its digits is 20000, while the sum is 33.

The spelling of 55154521221 in words is "fifty-five billion, one hundred fifty-four million, five hundred twenty-one thousand, two hundred twenty-one".